Some were inconsistent. However, it was such a hard punching era (the hardest IMO) that one slip-up and you were out of there. That isn't inconsistency. It's parity.
Most of them were inconsistent, im at work at the moment so cant detail it fully, however from what i know, the only elite 2 guys who were stopped by a single punch were Lewis and Moorer.
I could see Lewis and Holyfield taking a W from him. Christ knows what would happen in the inevitable series with each though.